US1169209A

US1169209A - Method of making pipe-bends.

Info

Publication number: US1169209A
Application number: US83536014A
Authority: US
Inventors: Charles H True; Neal Trimble Mckee
Original assignee: LOCOMOTIVE SUPERHEATER CO
Current assignee: LOCOMOTIVE SUPERHEATER CO
Priority date: 1914-04-30
Filing date: 1914-04-30
Publication date: 1916-01-25
Anticipated expiration: 1933-01-25
Also published as: AU1618215B

Description

C. H TRUE & N. T. McKEE.

METHOD OF MAKING PIPE BENDS.

APPLICAHON ILED APR 30 1914 SHEET 1.

Patented Jan. 25, 1916.

2 SHEETS 5W IN l/ENTOR CHARLES H. TRUE NEAL T. M KEE BY (L H. TRUE & N. T MCKEEx METHOD OF MAKING PIPE BENDS.

APPLlCATlON FILED APR 30. 1914.

Patented Jan. 25, 1916 2 SHEETS--SHEET 2,

WITNESSES 15*" llVl/E/VTUR A CHARLES H. TRUE By/VEAL 71/M /f/IE 4;; 3 3 9 A TTOR/VEYS CHARLES H. TRUE, OF HAMMOND, INDIANA, AND NEAL TRIIVIBLE MGKEE, OF DOBBS FERRY, NEW YORK, ASSIGNORS T LOCOMOTIVE SUPERHEATER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

METHOD OF MAKING PIPE-BENDS.

Application filed April 30, 1914;. Serial No. 835,360.

To all whom it may concern:

Be it known that we, Gunners H. TRUE and NEAL Tnnmne lhiol'inn, both citizens of the United States. residing, respectively, at Hammond, Indiana, and at Dobbs Ferry, New York, have inventedcertain new and useful Improvements in Methods of Making Pipe-Bends, of which the following is a specification.

Our invention relates to a method of making pipe bends, andparticularly to making what are com mouly knowii as U-shaped be'iids, such as are used in connection with boilers, superheaters and heating apparatus generally and exposed to high temperatures, or when used'to carry steam or fluidsunder pressure.

' Our invention relates particularly to making bends as aforesaid when the two legs of the bend are required to be very close together.

The object of our invention is to providea method of making a strong and durable bend which can be practised easily, eeonomically and at small expense.

A further object of our invention is to provide a method of making a bend as specified in which the internal or free cross-sectional area may be, at all points, fully as great, if not greater, than that of the indi vidual pipes joined by the bend.

Still. afurther object of our invention is to provide a. method of making a bend which,

i when employed as part of a superheater element of a smoke tube superheater, will not unduly restrict the flow of gases through the flue tube but will, on the other hand, facilitate the easy passage of said gases while, at the same time, exerting no greater retarding efiect upon the flow of steam through the bend than would be exerted by the same length of the pipe joined by said bend.

Various ways of making bends for snmlar purposes have been proposed, but such ways are attended bycertain disadvantages which it is the purpose of our invention to obviate.

Our invention will. be better understood by referring to the accompanying drawings which show preferred devices for carrying out said invention. in whieh- Figure 1 represents a. plan view-of a pair of pipe ends in position .on the lower half of the female forming die preparatory to hav- Specification of Letters Patent.

.which are to be around into the pipe lengths may rest.

I a pair of tapered legs 9, united Patented Jan. 25, 1916.

ing our improved pipe bend formed thereon; Fig. 2 is an end view of Fig. 1 with the upper half of the female forming die in position; Fig. 3 is a view similar to Fig. 1,

showing the male forming die in position 7 is a section along the line 7 7 of Fig.

6 except that the upper member of the forging die is shown in position; Fig. 8 is a view, similar to Fig. 6, showing the pipe bend after the forging dies of'Fig. 7 have done their work; Fig. 9 is a section taken along the line 99 of Fig. 8;-Fig. 10 is a plan view of the completed pipe bend; Fig; 11 is an edge view of Fig. 10; Fig. 112is a section taken along the line l2-12 ofFig. 10; and 13 is a section taken along the line 13-13 of Fig. 10.

In the drawings, two pipe lengths 1, 2, united by a pipe bend, are squared off at one end, as at a and clamped between two similar halves 3, at of a female forming die. The lower member 4 of this die is shown in Fig. 4 and comprises a block having parallel semi-circular grooves 5 corresponding to the pipe diameter. The intermediate partition wall'orseptum between the grooves has one part 6 of the same height as the outer part of the die and another part 7 which rises gradually from a minimum height just before it joins the part 6 which it does by gentle curves which are carried grooves 5. Before placmg the pipe lengths in the

dies

3 and 4, their ends are raised to a welding heat. The

dies

3 and 4 must be securely clamped together, and it is best, also, to clamp the pipe lengths outside of the dies and to provide stops (not shown) against which the other ends of the The pipe lengths being inposition, as above described, a breaches die 8, comprising by web 10 and having slightly pointed ends 11 for easy I insertion, is held by the shank 12 in a suitable presstnot shown) and has its legs in sorted into the pipe ends at a and is pushed home therein. As the web 10 reaches the inner adjacent walls 13 of the pipe ends, its a comparatively sharp thin edge 13 will slit said walls and raise andl yer the slitted wall portions against the parts 7 belonging to the upper and lower die respectively and compress said; slitted portions between the parts 7 and the web 10, which thickens toward its base so as to conform to the varying height of the part 7. If the dimensions of the forming dies and of the breeches die are properly chosen, the upper and lower pair of slitted pipe walls will just properly abut with welding pressure when the edge of the web 10 is distant from the end of the part (iof the septum lying between grooves 5 by substantially the wall'thickness of the pipe. A perfect weld will thereby be formed, As will be evident from Fig. 3 the web 10 whichunites the legs 8 has substantially the same shape as that of the space uniting the bores of the female forming die; but this web is smaller in section than said space and is everywhere separated from the parts 7 by an amount substantially equal to the wall thickness of the pipes. This separating distance might, however,,if desired, be greater at one point and less at another within the scope of the invention, the prime requisite being that the separating space must just take and contain the slitted and spread pipe walls so asto bring their edges together with the necessary pressure to effect a satisfactory weld. The breeohes dies is then withdrawn, the forming die opened, and the pipe lengths with the partially completed bend removed. Atthis stage in theoperation, the pipe bend will have the appearance shown in Figs. 6 and 7, that is to say, the two pipes will be parallel to one another, and will retain their original shape at their ends, except in the connecting region or yoke between them formed by the slitted parts of the pipe walls, which have been raised and lowered respectively and welded. together as aforesaid. It will now .be necessary to suitably close the ends of the partially completed bend and at the same time to give said bend a suitable shape. These two operations may be carried outsimultaneously as follows: The forging die 15, comprising similar members, is used'in any suitable forging machine (not shown) after i the manner shown in Fig. 7. The preferred form of. the two similar members of this forging die is indicated in Fig. 5 where the one part 16 is scooped out to correspond with the conformation of the com leted bend, while another part 17 is recessed y an amount substantially equal to the thickness ofythe pipe wall. A central recess 18 is comprised between the parts and provided at one end to'receivd a slipdie 19 which is inserted centrallyfinto the par tially formed bend as shown in Fig. 6. With the inchoate pipe bend in position, as shown in. Figs. 6 and 7, the forging dies are lightly operated so as to elfect a preliminary shaping. As soon as the central portion of the bend is flattened sufficiently to bind upon the slip die, the latter is withdrawn. The forging operation is then continued until the bend has assumedthe appearance shown in Figs. 8 and 9 where, so far as its form is concerned, it is complete except for the fin 21 resulting from the flattening of the surplus wall-portions lying outside of the curve which is to form the outer boundary of the completed bend. ,The'small opening left at the end of the die by the withdrawal of the slip die should have been closed by any suitable means before the completion of the described forging operation. although, if preferred, it may be closed after the remainder of the forging operation has been completed. Or, after the slip die has been removed we may remove the incomplete pipe bond, as it thus exists, to a second pair of forging dies similar to those just described but having'no recess 18 for the slip die. This second pair of dies will thus close the slip die opening as well as the remainder of the pipe bend opening. It now remains to remove this fin 21' and this, we find can be most easily done by using an city-acetylene burner and running' around the pipe end at the line of its junction with the fin so as to'cut the fin away. By thenagain running the flame around the curved end whileprojecting it into the plane of separation of the edges, the latter will be welded together in a firm and durable weld. Or the fin may be cut oif by shearing in a suitable trimmingpress, or the equivalent, before proceeding to weld he edges together. v Instead of proceeding fromthe incomplete bend of Fig. 6 through the, form of Figs. 8 and 9, z. e., instead of first compressing the ends so as to form the fin 21, and then cutting off said fin and welding the edges together, as just described, we may, if we prefer, first shear off all that portion of the incomplete bend (Fig. 6) which lies between the extreme ends and thecurved line b. The edges at said line b may then be brought together by suitable forging dies, or by other suitable means, and then welded igogether bythe oxyacetylene flame, as beore.

Other methods ofbringing the edges (at the curve 6) together orof welding them durably when-brought together, may be employed within the spirit of our invention.

. By suitably shaping the forming dies the end 0. of our improved pipe bend may be formed as a sharpedge from which the 40 lack of uniformity among different bends as well as inefficiency in individual bends.

. thickness of the pipes proper when .and bend merge into one another.

pipes The bend is not quite so thick through the yoke 14 as at .the sides thereof, in the particular form of bend which has been described, this lessened thickness resulting, in effect, in the production of a central groove on each side of the bend. The fire gases, as they reach the end 0 of the bend, are split and divide and pass on past the bend, the two grooves facilitating the passage of the gases and, at the same time, providing a larger heating surface for thegases to contact with. This groove is, however, not es sential to the practice of our invention and may be omitted. Indeed, the form and proportions of the bend maybe varied widely without departing from the spirit of the invention and the section through the bend (as shown in Fig. 13) may have any desired and convenient form.

The cross-sectional area of the passage I through the pipe bend, at all points thereof,

can obviously be fully as great as that of the pipe itself, and as much greateras may be desired. .This is accomplished by choosing a suitable length" and thickness for the web l0 and by correspondingly dimensioning the forming'dies with which-the web must cooperate.

When the pipe bend, made as above de-' scribed, is completed (Figs. 10-12) it is' practicallyimpossible to find the welds, 'so perfectly and smoothly are the edges united. In particular, there will be no fins projecting inwardly from the welds; such fins 005 I our in certain other methods of pipe bend manufacture and are very diflicult if not impossible to remove. If left in place such fins will restrict the passage and produce a employedin shaping the bends and making the welds, may be .made-within the spirit of our invention as defined in the following claims '-1.-The method of'.making pipe bends which comprisestakingtwo pipes and slitting the wall of each longitudinally for a suitable distance from the pipe end, pressing thepipe walls on each side of said slits outwardly, causing the edges of the two slitted parts of one pipe to abut against corresponding edges of the other pipe and then welding said edges together, and finally.-

- closing the end of the incomplete bend thus formed.

2. The method of making. pipe bends which comprises taking two pipes and slitting the wall of each longitudinally for a suitable distance from the pipe end, pressing the pipe walls on each side ofsaid slits outwardly, pressing the edges of the two slitted parts .of one pipe forcibly against corresponding edges of the other pipe while said edges are at welding heat thereby causing them to be united, and-finally closing the end of the incomplete bend thus formed.

3. The method of making pipe bends which comprises holding two pipe lengths to be joined in the relative position they are to occupy when the bend is completed,-si-

multane'ously slitting neighboring walls of a pressing the slitted parts outwardly until they abut. in-pairs, welding said abutting edges together, and finally closing the end of the incomplete bend thus formed.

5. The method of making pipe bends I which comprises holding twopipe lengths to be joined in the relative position they are to occupy when the bend is completedand with their ends at welding heat, slitting neighboring walls of both pipes for a suitable distance from said ends, pressing the pipe walls on each side of each slit out'-. wardly until said edges are abutted forcibly together in pairs thereby uniting them by a.-

complete bend thus formed.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

CHARLES H. TRUE; NEAL TRIMBLE MoKEE.

lVitnesses as to C. H. True:

M. J. SoNTAe, JAS. K. Sco'rr. Witnesses as to N. T. McKee:

W. SCHILLER. G. H. WINKIJER, Jr.

weld, and finally closing the'end of the in-